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    <title>何为数据代理</title>
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<!-- 数据代理：通过一个对象代理队另一个对象中属性的操作，包括读和写 -->

<script type="text/javascript">
    let obj1 = {x: 100}
    let obj2 = {y: 200}
    Object.defineProperty(obj2, 'x', {
        get() {
            return obj1.x;
        },
        set(v) {
            obj1.x = v;
        }
    })
</script>

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